How to find the number of significant figures when doing chemistry calculations

I know there are different rules for how to get the amount of sig. figs. (such as adding, subtracting, multiplication, and division). Which rules apply to which and how to do so?

Multiplying and dividing- take the amount of sig figs as the one with the fewest. For instance, 1.24757*2.0 would receive 2 sig figs, as 2.0 has only two sig figs.

Adding and subtracting- take the amount of sig figs as the one with the fewest decimal places. So 32.23+1.3 would have one decimal place, as 1.3 only has one decimal place (the numbers before the decimal do not count here)

Remember, zeroes at the beginning of a number are never significant (0.007 has 1 sig fig)
Zeroes at the end are significant only when there is a decimal place (1000 has 1 sig fig, but 1000. has 4 sig figs)

Also, the answerer above me has a good point: never round until the very end of your calculation. Doing so skews the final answer. Simply keep track of how many sig figs you will need at the end.

Adding or Subtracting values, you express the results to the LEAST accurate place value after correctly rounding off.
Example with Addition: 12.36+5.203+120.7= 138.263 (with significant figures the answer is: 138.3)

Example with Subtraction: 224.985-96.72= 128.265 (with significant figures the answer is: 128.26)

Multiplying or Dividing values, you express the results to the same number of sig figs (significant figures) as the value with the least number of sig figs.
Example with Multiplication: (4.520)(8.9)= 40.228 (sigfigs: 40.)

Example with Division: 123.45/ 16.4= 7.5274 (sigfigs: 7.53)

p.s. the sigfigs for logarithms is a bit different

Look at how many significant digits (figures) are given in the question.
Your final answer should have the same amount.
Generally you want to use 1-2 extra digits through all your calculations, then round at the very end to however many you were given.

google?